During the **2017-18** academic year, the School will have a special program on **Locally Symmetric Spaces: Analytical and Topological Aspects**. Akshay Venkatesh of Stanford University will be the Distinguished Visiting Professor. Alexander Goncharov, Laurent Clozel and Joseph Bernstein will be Members during term I.

The topology of locally symmetric spaces interacts richly with number theory via the theory of automorphic forms (Langlands program). Many new phenomena seem to appear in the non-Hermitian case (e.g., torsion cohomology classes, relations with mixed motives and algebraic K-theory, derived nature of deformation rings). One focus of the program will be to try to better understand some of these phenomena.

Much of our understanding of this topology comes through analysis ("Hodge theory"). Indeed harmonic analysis on locally symmetric spaces plays a foundational role in the theory of automorphic forms and is of increasing importance in analytic number theory A great success of such harmonic analysis is the Arthur-Selberg trace formula; on the other hand, the analytic aspects of the trace formula are not fully developed, and variants such as the relative trace formula are not as well understood. Thus analysis on such spaces, interpreted broadly, will be another focus of the program.

There will be two workshops during the academic year. The term I workshop, "Motives, Galois representations and cohomology around the Langlands program", will be held November 6-10, 2017. The term II workshop will be held March 5-9, 2018.